Consumer advocates are calling for more rigorous enforcement of insurance laws to protect borrowers from dubious credit-related products. In a letter sent last week to state insurance commissioners, the Consumer Federation of American and the Center for Economic Justice charged that borrowers last year paid $2.5 billion more for credit life and disability insurance than they should have. Meanwhile, loss ratios dipped to just 34.5 percent in 2000, from 42.5 percent five years earlier. On